Brasserie Blanc, the restaurant chain fronted by celebrity chef Raymond Blanc, is to almost double in size after acquiring steak-frites specialist Chez Gerard from administrators.

All eight Chez Gerard sites are to be rebranded as Brasserie Blancs at a cost of £4m, marking the end of a brand that has a 30-year history.

The future for Chez Gerard's sister brands, Livebait and Bertorelli, was less clear after parent company Paramount Restaurants called in administrators from Deloitte. Including Chez Gerard, the business operates 32 restaurants and employs 713 staff. Approximately 250 jobs will now be transferred to Brasserie Blanc.

Paramount was listed on the stock market until it was acquired by private equity house Silverfleet Capital in 2005. Four years later the ailing chain was effectively handed over to its lenders Royal Bank of Scotland and HSBC in a restructuring deal that included a £55m debt writeoff. It continued to struggle and the banks called in administrators on Thursday. It is not clear what price the administrators received.

The expansion of Brasserie Blanc taps into the increasing popularity of restaurant chains that are fronted by leading chefs. The acquired sites are all London locations, including the roof terrace at Covent Garden overlooking the Royal Opera House, as well as several properties in the Square Mile.

The deal will take the total number of Brasserie Blanc outlets to 19. At the same time Blanc and his business partners are developing a gastropub concept called White Brasserie.

In an earlier incarnation the business known as Petit Blanc was a adjunct to the Michelin-starred restaurant at Le Manoir aux Quat'Saisons hotel near Oxford.

It struggled initially and was eventually bought out of administration by a team of restaurant entrepreneurs led by Mark Derry, the founder of Loch Fyne restaurants. Derry sold it to pub group Greene King in 2007 for £70m.

Derry has since built up the business in partnership with Blanc, who remains heavily involved as a director and oversees the menu. However the business is run on a day-to-day basis by experienced restaurant chain executive John Lederer, who was previously responsible for running the Chez Gerard brand he is now to close.

The trend for celebrity chef branded restaurants has led to the rapid success for Jamie's Italian chain, part of Jamie Oliver's business empire, as well as the mixed success of Gordon Ramsay's foray into upmarket gastropubs.

The endorsement power of top chefs has been increasingly exploited as a marketing tool by retailers from supermarket to roadside fast food chains. Heston Blumenthal was recruited by Little Chef to refresh its menu in what was regarded by some as primarily a publicity exercise.

Meanwhile, Marco Pierre White has used his name to endorse Knorr stock cubes, which he advertises on television.